This study aims at making the relationship between the deterministic approach and the probabilistic approach in the structural earthquake response analysis clear by graphically depicting the constraint curves for responses. The present aseismic design of a structure is carried out by deterministic approach using the response spectrum and modal analysis. As most structures face random external forces, however, it is necessary to introduce the probabilistic concept into the aseismic design.
In this study, the authors have formulated the structural earthquake response analysis by two approaches: one is the deterministic approach using the response spectrum and modal analysis, while the other is the probabilistic approach using the power spectrum density, random vibration theory and dynamic reliability analysis.
Some structures of multi-degrees-of-freedom were analyzed by the two approaches, and the constraint curves for these responses were graphically illustrated. From these results, it is shown that the constraint curves determined by the deterministic approach are quite similar to those determined by the probabilistic approach. A quantitative relationship between the two responses has been obtained by evaluating these constraint curves.
